A new study from the University of Virginia finds that brain speed, and the ability to memorize patterns and unrelated material, like random words, all seem to peak in our early 20's.
Then around age 27, researchers found these abilities start to decline.
The declines are slight, no one would notice them in everyday life.
Of course, some people may recall their 20-year old brains weren't great at making good decisions.
Researchers say that while it's true they found some aspects of cognitive functioning seem to change fairly early in adulthood, they are only one measure of how well your brain functions overall.
They say knowledge and experience continuously increases.
The study included about 2,000 healthy adults aged 18 to 60. They were tested on mental agility with puzzles and other cognitive tests.